Atmos Energy INTERCOMBI HE32 - Manual (Page 43)

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13. Exit the test mode by simultaneously pressing the “+” and “–“ buttons on the
operating panel. Replace the dust cap (A) and close the flue gas measuring
nipple.
14. Remount the front cover of the appliance.
Caution: Check the measuring nipples used for gas tightness.
Caution: On windy days or on installations with a long flue run it is necessary to
replace the front cover of the boiler in order to obtain an accurate CO
2
measurement
Setting the gas valve by pressure measurement
This method is less accurate, but usually gives a sufficient result.
1. Switch off the appliance using the On/Off button (
- on service display).
2. Remove the front cover of the appliance.
3. Turn the measuring nipple (C) on the gas valve open with two turns and connect
this through a tube to the plus connection of the pressure gauge.
4. Switch on the appliance using the On/Off button.
5. Set the boiler to the lowest output by simultaneously pressing the “Service” and
“–“ buttons on the operating panel until an L appears on the service display.
6. Read the pressure. This should be about -5 Pa or -0.05 mBar (min. –10 Pa,
max. 0 Pa. or min.–0,1 mBar, max. 0 mBar). When this is not the case, proceed
as follows for setting:-
7. Remove the dust cap (A) with a torx T15 driver.
8. Set the pressure using setting screw (B) (clockwise higher and counter-
clockwise lower).
9. After measuring and setting, replace the cover cap A and close the measuring
nipple (C) again.
10. Remount the front cover of the appliance.
Caution: Check the measuring nipples used for gas tightness.
7.10 Carbon monoxide : carbon dioxide ratio
Atmos recommends that a carbon dioxide : carbon monoxide ratio test is carried out
when the boiler is commissioned. This is best done when the CO
2
content of the flue
gasses is measured. See the procedure described in § 7.9.
1. Set the boiler to the lowest output by simultaneously pressing the “Service” and
“–“ buttons on the operating panel until an L appears on the service display.
2. Measure the CO/CO
2
ratio.
3. Set the boiler to the high output by simultaneously pressing the “Service” and “+“
buttons (twice) on the operating panel until an H appears on the service
display.
4. Measure the CO/CO
2
ratio
The CO/CO
2
ratio at low or high output should be no higher than 0.004.
A CO/CO
2
ratio between 0.004 and 0.008 means that the appliance is ‘At Risk’ (AR).
A CO/CO
2
ratio above 0.008 means that the appliance is ‘Immediately Dangerous’
(ID)
Where an ‘at risk’ or ‘immediately dangerous’ situation is encountered, measures
must be undertaken to rectify the situation. Particular attention should be given to
the gas/air ratio, the integrity of the flue, or blockage in the heat exchanger. Contact
the manufacturer for assistance.